Besides meeting your manager and your team, hosting your first team meeting, and possibly completing your induction training, the rest of your first week as a manager should be spent doing the following three things.
Your first week
Meet your stakeholders
If you are now a Project Manager, then you may well have a large number of stakeholders, starting with the people who are performing the seven fundamental roles on your software project.
Although your relationship with them will be more transactional in nature, compared to a direct team you manage, when you take the time to formally and purposefully introduce yourself, your working relationship will get off to a better start.
It's not such a nice experience for a project team...